Air Seal your attic before insulating


When one pops there head into the attic they may see something similar to the first picture & think that hey, I need some more insulation. I have lost count of how many people have simply seen something on TV or had an "energy audit" done where they recommended more insulation & I get called in later as they are still uncomfortable or having issues.
While I agree that the attic below definitely needs more insulation, there were a few things that need to be dealt with first. You see in order for insulation to work optimally it needs to be enclosed on all six sides which needless to say, doesn't fly when it comes to an attic. That is one reason why the R-Values are nearly doubled or tripled in the attic area when compared to walls. So what happens when you add air-leakage underneath – well it really cuts down on its performance.
While we had to remove the insulation in this area of the house,that is not always the case. If you don't have issues with mice, etc... you can simply move it out of the way & fix the problem areas. Some of the most common spots are;
· Wire & plumbing penetrations – use appropriate foam or caulk
· Drywall edges – foam or caulk
· Chases & soffits – foam board, drywall, or plywood to cap
· Around electrical boxes & exhaust fans - foam or caulk
· Stoves & furnace vents – this is a big "it depends" & sometimes is best left to a professional (especially for fireplaces), but fire rated caulk / foam & Roxul are commonly used
· Recessed lights – is it IC rated or Non-IC rated (http://blog.sls-construction.com/2011/rip-recessed-light)
Is that the end... no as this attic had 2 bathroom vents that simply dumped their moisture in the attic, baffles that were non-existent and a few other items. Alas those are special issues that easily take up a full piece themselves.
This post is a modified version of http://blog.sls-construction.com/2011/air-sealing-attic-penetrations.If you are considering or having this work done we encourage you to check out the full article & the rest of the http://blog.sls-construction.com/category/tips/air-sealing-insulation series.
Shoot, this doesn't look too bad... let's just spray some more cellulose in there & well be good, right? Well maybe not so fast
Shoot, this doesn't look too bad... let's just spray some more cellulose in there & well be good, right? Well maybe not so fast
Eek, guess we might have a few other things to fix & so glad I put that respirator on (If you do have mouse or other droppings, the old insulation needs to be removed)
Eek, guess we might have a few other things to fix & so glad I put that respirator on (If you do have mouse or other droppings, the old insulation needs to be removed)
Guess what happens if you pay someone to add more insulation & they come across an area like this
Guess what happens if you pay someone to add more insulation & they come across an area like this
Ahhh the sins one can hide under insulation
Ahhh the sins one can hide under insulation
Three guesses where the mice were coming up... in order to close these areas up you can use plywood, drywall or foam board – in this case we were redoing the bathrooms & eliminated the chase all together
Three guesses where the mice were coming up... in order to close these areas up you can use plywood, drywall or foam board – in this case we were redoing the bathrooms & eliminated the chase all together
Ready to go – fans now vented outside, all air leakage paths foamed or caulked & electrical junction boxes flagged in case one needs to find them later
Ready to go – fans now vented outside, all air leakage paths foamed or caulked & electrical junction boxes flagged in case one needs to find them later

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2 of 9 comments
  • Jack Moore
    on Dec 30, 2015

    This was really helpful, and would be to anyone wondering how to increase the effectiveness of their home insulation. I know too many people who completely ignore insulation, and don't consider how important it is to their energy efficiency and safety. I'm glad I read this, and I'll likely recommend it to all of my homeowner friends. http://www.perthinsulationsupplies.com.au

  • John White
    on Jun 4, 2018

    This article is really helpful for those who wondering about the insulation to increase the effectiveness of their home insulation. Proper attic insulation and restoration will seal the gaps or cracks that might permit moisture heat, pest to enter your attic, In addition of that it also helps you to reduces energy expenses during chilling summer season by producing cool temperature inside home and resisting heat transfer from warm air outside. You should try to contact HVAC maintenance provider near you.

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